Wet/dry automatic injector assembly

• US 6,702,778 B2
• Filed: 06/08/2001
• Issued: 03/09/2004
• Est. Priority Date: 06/08/2000
• Status: Expired due to Term

• Current Assignee: Meridian Medical Technologies Incorporated
• Original Assignee: Meridian Medical Technologies Incorporated
• Inventors: Wannarka, Gerald L., Wilmot, John G., DʼErasmo, Maria Cristina, Hill, Robert Leavitt
• Primary Examiner(s): Casler, Brian L.
• Assistant Examiner(s): DESANTO, MATTHEW F
• Application Number:
  US09/876,255
• Publication Number:
  US 20020016563A1
• Time in Patent Office: 1,005 Days
• Field of Search: 604/85, 604/91, 604/90, 604/92, 604/84, 604/191, 604/236, 604/82
• US Class Current: 604/85
• CPC Class Codes: A61M 2005/206 With automatic needle insertion
• CPC Class Codes: A61M 2005/2073 preventing premature release, e.g. by making use of a safety lock
• CPC Class Codes: A61M 5/2033 Spring-loaded one-shot injectors with or without automatic needle insertion multishot dosing syringes A61M5/31525, needle insertion only A61M5/3287
• CPC Class Codes: A61M 5/2066 comprising means for injection of two or more media, e.g. by mixing
• CPC Class Codes: A61M 5/2448 comprising means for injection of two or more media, e.g. by mixing
• CPC Class Codes: A61M 5/286 upon internal pressure increase, e.g. pierced or burst A61M5/283 takes precedence
• CPC Class Codes: A61M 5/3145 Filters incorporated in syringes

Abstract

The present invention is directed to an automatic injection device containing a pre-loaded charge of medicament for automatically self-administering the medicament upon actuation thereof. The automatic injection device includes a dry compartment located within a housing for storing a predetermined dry charge of the medicament therein, a wet compartment within the housing for storing a predetermined amount of liquid injection solution therein, an activation assembly for causing the liquid injection solution in the wet compartment to be transferred to the dry wet compartment, and at least one compression assembly for maintaining the medicament located in the dry compartment under a continuous compressive state as the liquid injection solution passes through the dry compartment.

Claims

1. An automatic injection device containing a pre-loaded charge of medicament for automatically self-administering the medicament upon actuation thereof, said automatic injection device comprising:

a housing assembly;

a dry compartment for storing a predetermined dry charge of dry medicament therein;

a wet compartment for storing a predetermined amount of liquid injection solution therein;

a pre-loaded activation assembly for causing the liquid injection solution in said wet compartment to be transferred to said dry compartment, wherein the pre-loaded activation assembly automatically supplies a driving force upon activation to transfer the liquid injection solution in the wet compartment to the dry compartment, wherein the dry medicament dissolves in the liquid injection solution as the liquid injection solution passes through said dry compartment;

at least one dynamic spring compression assembly for maintaining the dry medicament located in said dry compartment under a continuous compressive state as the liquid injection solution passes through said dry compartment, wherein at least a portion of a compressive force acting on the dry medicament located in said dry compartment is provided by said at least one dynamic spring compression assembly; and

a needle assembly for dispensing the liquid injection solution containing the medicament dissolved therein.

2. The automatic injection device according to claim 1, wherein said at least one spring compression assembly is located within said dry compartment.

3. The automatic injection device according to claim 1, wherein said at least one spring compression assembly includes an expandable assembly, wherein said expandable assembly expands within the dry compartment as the medicament located within said dry compartment dissolves within the liquid injection solution.

4. The automatic injection device according to claim 3, wherein the expandable assembly includes a spring assembly and at least one plate to apply pressure on the medicament within said dry compartment.

5. The automatic injection device according to claim 4, wherein said at least one plate permits the passage of the liquid injection solution therethrough.

6. The automatic injection device according to claim 1, further comprising a releasable liquid barrier assembly for selectively preventing passage of the liquid injection solution from said wet compartment to said dry compartment at predetermined conditions.

7. The automatic injection device according to claim 6, wherein said releasable liquid barrier assembly permits the passage of the liquid injection solution to the dry compartment in response to a predetermined liquid pressure build up within said wet compartment.

8. A method for administering an injection of medicament injection solution to a patient using an automatic injection device, said method comprising:

locating an injection end of the automatic injection device adjacent a desired injection site on the patient;

activating a pre-loaded drive to automatically advance a collet into a wet compartment of the automatic injection device to pressurize the liquid injection solution in the liquid compartment and to cause an injection needle of the automatic injection device to advance and protrude through the injection end of the automatic injection device;

wherein the pressurization of the liquid injection solution causes the liquid injection solution to pass into a dry compartment adjacent the wet compartment where the liquid injection solution mixes with a compressed dry medicament to form a medicament injection solution which is then transmitted through the injection needle to the injection site where it is administered to the patient; and

maintaining the compressed dry medicament under a continuous compressive state using at least one dynamic spring compression assembly located within the automatic injection device.